Production of Biodiesel from Crude Neem Oil Feedstock and the Effects of Various Parameters on the Yield of Biodiesel

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International Journal of Research (IJR)

e-ISSN: 2348-6848, p- ISSN: 2348-795X Volume 2, Issue 08, August 2015

Available at http://internationaljournalofresearch.org

Production of Biodiesel from Crude Neem Oil Feedstock and the

Effects of Various Parameters on the Yield of Biodiesel

Anand Prakash Mall

M.Tech (Thermal) Scholar, Delhi Technological University (DTU), New Delhi, India Mb No: +919415879658: E-mail:anandwrites@gmail.com

ABSTRACT

Currently, most of the biodiesel is produced from the edible/refined type oil using methanol and alkaline catalyst. However, large amount of non-edible type oils and fats are available in our country. In this study, crude neem oil is used as alternative fuel for biodiesel production. The difficulty with alkaline transesterification of these oils has contained large amounts of free fatty acids (FFA). These free fatty acids quickly react with the alkaline catalyst to produce soaps that inhibit the separation of the ester and glycerin.

A two-step transesterification process is developed to convert the high FFA oils to its mono-esters. Using 100 ml of oil, the optimum combination of parameters for pretreatment were found to be 0.45 v/v

methanol-oil-ratio, 0.5% v/v H2SO4 acid catalyst, 50˚C and 45 min reaction time. After pretreatment of

neem oil, transesterification reaction was carried out with 4.5:1 methanol-to-oil molar ratio, 1% KOH as alkaline catalyst, 75 min reaction time and 50˚C reaction temperature to produce the fatty acid methyl ester. This two step process gave maximum average yield of 70±2%.

Key Words: Experimentation, Acid esterification; Alkaline transesterification; Neem Oil (Azadirachta indica); Neem Oil Methyl Ester (Biodiesel)

1. INTRODUCTION:

The use of alternative fuels instead of

conventional fossil fuels is becoming

increasingly significant due to decreasing petroleum reserves and increasing greenhouse gases, all of which lead to global warming, ozone depletion and political and health concerns (Fukuda et al., 2001). Plant oils have been used as alternative fuels for many years, since they are renewable and readily available. However, these oils cannot be used directly as fuel sources in diesel engines due to: (a) high viscosity which leads to poor fuel atomization during the injection process, (b) low volatility and (c) polymerization which results in deposit formation, incompletion combustion and poor emissions (Ma and Hanna, 1999). To overcome these disadvantages, oils can be converted into fatty acid methyl esters (FAME) which are also known as biodiesel. Biodiesel is an alternative fuel that is non-toxic, completely biodegradable

and renewable and can be adapted easily without any modification to diesel engines.

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transesterification process plays a vital role, in order to overcome these disadvantages.

The process of displacing alcohol from an ester to form another ester is called transesterification. Transesterification is the most simple and efficient method to produce biodiesel by using acids, alkalis, or enzymes as catalysts. Triglycerides with high free fatty acid and water contents are not essential for a biodiesel conversion process using an acid catalyst. However, the reaction rates are slower than those of the alkali catalytic process (Freedman et al., 1986). The alkali-catalysis transesterification process has been widely used in the biodiesel industry, because it gives a high yield of conversion of fatty acid methyl esters from triglycerides at low temperatures and pressures in a relatively short reaction time of 4-10 hours. However, it has several drawbacks including product separation, soap formation and negative environmental impacts such as greenhouse gas, CO, hydrocarbons, NOx and particles in exhaust emissions (Nielsen et al., 2008).

Neem is a tree in the family ‘maliaceae’ which grows various parts in Bangladesh. It’s scientific name ‘Azadirachtaindica’. The evergreen tree is large, reaching 12 to 18 meters in height with a girth of up to 1.8 to 2.4 meters. The seeds have 40% oil which has high potential for the production of biodiesel. It has a higher molecular weight, viscosity, density, and flash point than diesel fuel. Neem oil is generally light to dark brown, bitter and has a strong odor that is said to combine the odors of peanut and garlic [M.A. Fazal et al., 2011].

Neem comprises mainly of triglycerides and large amounts of triterpenoid compounds. It contains four significant saturated fatty acids, of which two are palmitic acid and two are stearic acid. It also contains polyunsaturated fatty acids such as oleic acid and linoleic acids [Muthu et al., 2010]

2.

MATERIALS AND METHODOLOGY:

2(i) Materials

Crude neem oil was purchased from local market. The magnetic stirrer with hot plate was at DTU laboratory. Chemicals are used in transesterification process like Pottassium hydroxide pellet (88% purity), Methanol (99% purity), Concentrated sulphuric acid and Sodium hydroxide pellet (88% purity).

2(ii) Equipment

A round bottom conical flask is used as reactor for these experimental purposes. A magnetic stirrer with hot plate arrangement is used for heating the mixture in the flask. The mixture is stirred at the same speed for all test runs. The temperature range of 40–60˚C is maintained during this experiment and its monitored by thermometer. The separating funnel is used to separate the methanol-water mixture after acid

pretreatment and the glycerol after

transesterfication.Three set of trail runs are carried out for each combination of parameter.

2(iii) Methodology

The aim of this study is to improve the process for producing biodiesel from crude neem oil. There are three processes such as

Oil filtration, Acid esterification

and alkaline transesterification. 2(iii)(a) Oil filtration

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100 ml of refined neem oil is poured into the flask and heated up to 60˚C. The 45% v/v methanol is added with the preheated neem oil and stirred for a few minutes. 0.5% of sulphuric acid is added with the mixture. Heating and stirring should continue about 45min at atmospheric pressure. After completion of this reaction, the mixture is poured into a separating funnel for separating the excess alcohol, impurities and sulphuric acid. The excess alcohol, sulphuric acid and impurities move to the top layer and it’s discarded. The lower layer is separated for further processing of transesterified into methyl ester. This process reduces the acid value of crude neem oil to less than 1% of FFA.Viscosity reduction increases with increase in methanol-to-oil ratio.

2(iii)(c) Alkaline transesterification

After acid pretreatment the esterified oil is taken in flask and heated up to 60˚C. 1% of KOH is dissolved in 30% (6:1 M) methanol. The dissolved solution is poured into flask. The mixture is heated and stirred for 1hr.On completion of reaction, the mixture is poured into separating funnel over 12 hr.The glycerol and impurities are settled in lower layer and it’s discarded. The impure biodiesel remain in upper layer. It contains some trace of catalyst, glycerol and methanol. The washing process can be done by the 3/4th of hot distilled water added with methyl ester and gently stirred. The upper layer is pure biodiesel and lower layer is drawn off. 3. RESULTS AND DISCUSSION:

3(i) Acid esterification:

3( i )(a) Effect of methanol-to-oil ratio

Two important parameter significantly affected the acid value. These are sulphuric acid concentration and methanol quantities. Molar ratio is defined as the ratio of number of moles of alcohol to number of moles of vegetable oil.

Theoretically, transesterification reaction

requires 3 moles of alcohol for each mole of oil. However, in practically molar ratio should be

higher than stoichiometric ratio. By varying

methanol proportion such as 0.35:1,

0.40:1,0.45:1, 0.50:1,0.55:1 methanol-to-oil

ratio, among these 0.45:1 gave higher yied.The last two 0.50:1, 0.55:1 have only slight variation. In economic view 0.45:1 proportion is selected for reaction condition. The effect of methanol variation is shown in fig.3(i)(a) from the figure conversion efficiency is slightly increase up to

0.45:1 methanol-to-oil ratio. After that

conversion efficiency is decreased with increase in methanol-to oil ratio because it leads to increasing the acid value. It has been determined that viscosity reduction increases with increase in methanol-to-oil ratio.

Methanol

to Oil Ratio(v/v)

0.35 0.40 0.45 0.50 0.55

Conversion Efficiency (%)

77 84 95 90 87

Fig.3(i)(a) Effect of Methanol-to-oil ratio on conversion efficiency

3( i )(b) Effect of acid catalyst amount

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0.70% v/v. Maximum conversion efficiency 95% is achieved in 0.5 % v/v H2SO4. Effect of acid catalyst variation is shown in fig. 3(i)(b) from the figure more than 0.5% v/v H2SO4, the product color is become black. Lower amount of sulphuric acid addition affects the final product yield.

Acid Catalyst %

(v/v)

0.3 0.4 0.5 0.6 0.7 Conversion

Efficiency (%)

67 72 95 82 77

Fig.3(i)(b) Effect of acid catalyst amount on conversion efficiency

3(i) (c) Effect of reaction temperature

The conversion efficiency is very low at room temperature even after 2 hr reaction .If increase in temperature the conversion takes place at higher rate. The optimum temperature is achieved at 50˚C.At high reaction temperature; the methanol is lost because melting point of methanol is 65˚C.Above 50˚C product color become black.

3(ii) Alkaline transesterification: 3(ii)(a) Effect of methanol-to-oil ratio

Molar ratio is very important factor for

transesterificatin reaction. Theoretically,

transesterification reaction requires 3 moles of alcohol for each mole of oil. However, in practically molar ratio should be higher than stoichiometric ratio. The higher molar ratio is required for complete the reaction at higher rate.

In lower molar ratio, it takes longer duration for complete the reaction. The effect of methanol-to-oil ratio on conversion efficiency is shown in fig.3(ii) (a) It has been seen that yield is slightly increase up to 4.5:1 methanol-to-oil molar ratio. The maximum methyl ester yield 69% is achieved at 4.5:1methanol to oil molar ratio. With further increase in methanol-to oil molar ratio the conversion efficiency is decreases.

Methanol to Oil Molar Ratio

3 4.5 6 7.5 Conversion

Efficiency (%) with 1% NaOH

41 60 51 46 Conversion

Efficiency (%) with 1% KOH

50 69 60 55

Fig.3(ii)(a) Effect of methanol on conversion efficiency

3(ii)(b) Effect of alkaline catalyst

The amount of catalyst variation is affecting the conversion efficiency. The catalyst proportion is varied from 0.75- 1.50% KOH. The effect of catalyst variation on conversion efficiency is shown in fig.3(ii)(b) From the figure yield is slightly increased up to 1% KOH and after that yield is decreased due to reverse reaction is take place (emulsion formation).The maximum yield is achieved of 70% at 1% KOH.

Alkaline Catalyst %(wt/wt)

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International Journal of Research (IJR)

Available at http://internationaljournalofresearch.org Conversion

Efficiency(%) by NaOH

52 62 55 50 Conversion

Efficiency(%) by KOH

62 70 65 60

Fig.3(ii)(b) Effect of alkaline catalyst amount on conversion efficiency

3( ii )(c) Effect of reaction temperature

The reaction temperature has important role in alkaline-catalyst transesterification .At room temperature no significant yield is notified for even 2hr reaction. The yield is increased with increase in reaction temperature. The effect of temperature variation on conversion efficiency is shown in fig.3(ii)(c). By varying temperature in four different levels such as 45, 50, 55 and 60˚C among these 50˚C gave maximum methyl ester yield. If greater than 50˚C, chance for loss the methanol. The maximum ester efficiency 72% is achieved at 50˚C.

Reaction

Temperature(⁰C) 45 50 55 60 Conversion

Efficiency (%) with 1% NaOH

54 66 64 58 Conversion

Efficiency (%) with 1% KOH

64 72 69 62

Fig.3(ii)(c) Effect of reaction temperature on conversion efficiency

3(ii ) (d) Effect of reaction time

The conversion rate is increased with increase in reaction time. In this experiment, reaction time varying from 55-85 min. The effect of reaction time variation on the conversion efficiency is shown fig.3(ii)(d) from the figure yield was slightly increased up to 75min reaction time and after that yield is decreased. The maximum efficiency is achieved of 68% for 75min reaction time. From these experiments the optimum yield is obtained at 75min reaction.

Reaction Time(min) 55 65 75 85 Conversion

Efficiency (%) with NaOH

48 52 58 49 Conversion

Efficiency (%) with KOH

58 62 68 59

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4. CONCLUSION

The high FFA (20%) content neem oil has been investigated for the biodiesel production. It has been found that the feedstock with high FFA its could not be transesterified with alkaline catalyst because the alkaline catalyst react with FFA to form soap. So in this study, two step processes was developed to convert FFA to its methyl ester. The first step is acid treatment it reduces the FFA content of oil to less than 1% using acid

catalyzed (0.5 % v/v H2SO4) reaction with

methanol (0.45 v/v) at 50˚C temperature and 45 min reaction time. After acid treatment alkaline transesterfication reaction was carried out at 1% w/w KOH, 4.5 methanols to oil molar ratio, 50˚C and 75 min reaction time. The maximum yield is 70±2%.The effect of molar ratio, catalyst; reaction temperature and reaction time are analyzed in each step process. Excess addition of sulphuric acid darkens the product and it leads to more production cost.

5. COST ANALYSIS:

Sl. No

Component Cost

(Rs.)

1 Sodium Hydroxide

(Catalyst) 23/kg

2 Potassium hydroxide

(Catalyst) 36/kg

3 Neem oil (Feedstock ) 150/

litre

4 Methanol (Alcohol) 35/

litre

5 Glycerin (By product of

Biodiesel)

75/ litre

Sl. No.

Component Cost

(Rs.)

1 Neem Oil – 100 ml 15

2

Two step

transesterification Cost - 65 ml(45 ml + 20 ml ) of Methanol [4.5 Methanol/Oil Molar Ratio ]

2.275

3 Catalyst KOH 1.0 gm 0.036

4 Recovery ( Glycerin 50 ml ) 3.75

5 Total Cost ( 1 + 2 + 3 – 4 )

17.311 – 3.75 = 13.561

Biodiesel production from 1 litre Neem Oil=0.70 Litre

So Cost of Biodiesel per litre = [(13.561 /100)*1000] / 0.70 = 193.73 Rs.

The cost of the biodiesel production can be minimized as possible to recover the used methanol. Recycling of methanol again and again in mass production and commercial use, the cost must be come to the lowest amount. Also the by-product such as glycerin and soap play an

important role to minimize the cost.

6. KEY REFERENCES

[1.] Abebe K. Endalew, Yohannes Kiros,

Rolando Zanzi. Heterogeneous catalysis for biodiesel production from Jatropha curcas oil (JCO). Energy 2011; Vol. 36: pp. 2693-2700.

[2.] Atul Dhar, Roblet Kevin, Avinash Kumar

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International Journal of Research (IJR)

Technology 2012; Vol. 97: pp. 118– 129.

[3.] Ayhan Demirbas. Progress and recent trends

in biodiesel fuels. Energy Conversion and Management 2009; Vol. 50: pp. 14 -34.

[4.] C. Martín , A. Moure , G. Martín ,E. Carrillo

, H. Domínguez , J.C. Parajó. Fractional characterization of jatropha, neem, moringa, trisperma, castor and candlenut seeds as potential feedstocks for biodiesel production in Cuba. Biomass Bioenergy 2010; Vol. 34: pp. 533-538.

[5.] Deepak Tanwar, Ajayta, Dilip Sharma, Y. P.

Mathur. Production and Characterization of Neem Oil Methyl Ester. International Journal of Engineering Research & Technology (IJERT) 2013; Vol. 2. : pp. 1896-1903.

[6.] Dennis Y.C. Leung, Xuan Wu, M.K.H.

Leung. A review on biodiesel production using catalyzed transesterification. Applied Energy 2010; Vol. 87: pp. 1083-1095. .

[7.] E.F. Aransiola, E Betiku, DIO Ikhuomoregbe

and TV Ojumu. Production of biodiesel from crude neem oil feedstock and its emissions from internal combustion engines. African Journal of Biotechnology 2012; Vol. 11: pp. 6178-6186

[8.] Freedman B, R. Butterfield and E. Pryde.

Transesterification kinetics of soybean oil. Journal of the American oil Chemists Society 1986; Vol. 63: pp. 1375-1380.

[9.] Fukuda H., A. Kondo and H. Noda. Biodiesel

fuel production by transesterification of oils. Journal of Bioscience and Bioengineering 2001; Vol. 92: pp. 405-416.

[10.] GT Jeong, HS Yang, DH Park.

Optimization of transesterification of animal fat ester using response surface methodology. Bioresour. Technol 2009; Vol. 100: pp. 25-30.

[11.] H.N.Pandey. Development of a New

Catalyst for Bio-diesel Production. Ist

International Conference on New Frontiers in Biofuels, DTU January 18-19, 2010, New Delhi.

[12.] H Ibrahim, A. S. Ahmed, I.M. Bugaje,

Dabo Mohammed, C. D. Ugwumma. Synthesis of Bulk Calcium Oxide (Cao) Catalyst and its Efficacy for Biodiesel Production. Journal of Energy Technologies and Policy 2013; Vol. 3. : pp. 14-16.

[13.] Jon Von Gerpen. Biodiesel processing

and production. Fuel Process Technol 2005; Vol. 86: pp. 1097–1107.

[14.] J.M. Marchetti, A.F Errazu.

Esterification of free fatty acids using sulfuric acid as catalyst in the presence of triglycerides. Biomass. Bioenerg. 2008; Vol. 32: pp. 892–895.

[15.] Juan Calero, Gema Cumplido, Diego

Luna , Enrique D. Sancho, Carlos Luna , Alejandro Posadillo, Felipa M. Bautista , Antonio A. Romero and Cristóbal Verdugo-Escamilla, Production of a Biofuel that Keeps the Glycerol as a Monoglyceride by Using Supported KF as Heterogeneous Catalyst . Energies 2014; Vol. 7: pp. 3764-3780.

[16.] L.C. Meher, D. Vidya Sagar, S.N. Naik.

Technical aspects of biodiesel production by transesterification – a review. Renew. Sustain. Energy 2006; Vol. 10: pp. 248-268.

[17.] Madhu Agarwal, Kailash Singh, Ushant

Upadhyaya and S P Chaurasia, Potential vegetable oils of Indian origin as biodiesel feedstock – An experimental study. Journal of Scientific & Industrial Research 2012; Vol. 71: pp. 285-289.

[18.] Maryam Hassani, Ghasem D Najafpour,

Maedeh Mohammadi and Mahmood Rabiee.

Preparation, Characterization and

(8)

International Journal of Research (IJR)

[19.] M. A. Hanna, Loren Isom and John

Campbell, Biodiesel; Current perspectives and future. Journal of Scientific & Industrial Research 2005; Vol. 64: pp. 854-857.

[20.] F. Ma, M. A. Hanna. Biodiesel

production: a review. Bioresour Technol 1999; Vol. 70: pp. 1–15.

[21.] Md. Hasan Alia, Mohammad Mashud,

Md. Rowsonozzaman Rubel, Rakibul

Hossain Ahmad, Biodiesel from Neem oil as an alternative fuel for Diesel engine. Procedia Engineering 2013; Vol. 56: pp. 625 – 630.

[22.] M.A. Fazal, A.S.M.A. Haseeb and H.H.

Masjuki. Biodiesel feasibility study: An

evaluation of material compatibility;

performance; emission and engine durability. Renew. Sustain. Engy Reviews 2011; Vol.15: pp. 1314-1324.

[23.] Module 5, Lecture 4. Design for

Reliability and Quality. IIT, Bombay.

[24.] Muthu, V. SathyaSelvabala, T. K.

Varathachary, D. Kirupha Selvaraj, J. Nandagopal and S. Subramanian. Synthesis of biodiesel from neem oil using sulfated zirconia via tranesterification. Brazilian Journal of chemical Engineering 2010; Vol. 27: pp. 601-608.

[25.] N.Satya Sree, V.Madhusudhan Rao,

P.Vijetha. Production of Bio-Diesel From Soap Stock of Cotton Seed Oil By Using Ferric Sulphate Catalyst Via A Two Step Heterogeneous Catalysis: Characteristics of Bio-Diesel Produced. International Journal of Scientific & Technology Research 2014; Vol. 3. : pp. 141-144.

[26.] Nielsen P. M., J. Brask and Fjerbaek.

Enzymatic biodiesel production: Technical and economical considerations. European Journal of Lipid Science 2008; Vol. 110: pp. 692-700.

[27.] Olugbenga Olufemi Awolu and Stephen

Kolawole Layokun. Optimization of two-step

transesterification production of biodiesel from neem (Azadirachta indica) oil. International Journal of Energy and Environmental Engineering 2013; Vol. 4. : pp. 1-9.

[28.] Padmarag Deshpande, Kavita Kulkarni,

A.D.Kulkarni. Supercritical Fluid

Technology in Biodiesel Production: A Review. Chemistry and Materials Research 2011; Vol. 1. : pp. 27-32.

[29.] Poonam Gera, S.K.Puri and M.K. Jha.

Use of Basic Heterogeneous Catalysts for Biodiesel Production: A Review. Ist International Conference on New Frontiers in Biofuels, DTU January 18-19, 2010, New Delhi.

[30.] Suman Singh, P.K.Omre, Kirtiraj

Gaikwad. Standardization of Process

Parameters for Neem Oil & Determination of Properties for Using as a Fuel. International Journal of Engineering Research and General Science 2014; Vol. 2. : pp. 1-7.

[31.] Talebian-Kiakalaieh, N. A. S. Amin, A.

Zarei, H. Jaliliannosrati. Biodiesel Production from High Free Fatty Acid Waste Cooking Oil by Solid Acid Catalyst. Proceedings of the 6th International Conference on Process Systems Engineering (PSE ASIA) 25 - 27 June 2013, Kuala Lumpur.

[32.] Vivek and A. K. Gupta. Biodiesel

production from karanja oil. Journal of Scientific & Industrial Research 2004; Vol. 63: pp. 39-47.

[33.] V. Manieniyan, R.Senthilkumar and Dr.